This interrupted case study explores the scientific, legal, and societal complexities of repurposing an illicit substance, 3,4-methylenedioxymethamphetamine (MDMA), also known as "Ecstasy" or "Molly," into a clinically accepted medicine for treating post-traumatic stress disorder (PTSD).  Students first learn about the neuroanatomical basis for PTSD and its clinical distinction from anxiety and depression, and then critically evaluate the benefits and risks of a selective serotonin reuptake inhibitor (SSRI), sertraline (brand name Zoloft), in comparison with MDMA.  The activity concludes with a panel discussion in which students assume the roles of various clinical and regulatory experts to recommend the best treatment option for the character described in the case narrative. Students will learn to identify benefits and risks of an approved medicine by reading its drug label and to critically evaluate human clinical data published in primary literature.  This case has been used in undergraduate medicinal chemistry and neuropharmacology courses and is suitable for a variety of introductory undergraduate or graduate courses in psychology, biochemistry, pharmacy, public health, and biomedical sciences.